How to show the edge color from imported '.ply' file?
I know this isn't a complete solution, but I hope it will help you plan your next steps.
First read this: File format with per face colors
Blender isn't importing any colors from your .ply, so either it's a shortcoming in Blender, or the file isn't properly formated.
Once you managed to get the colors, use the material setup below. Where mine says &quot;Col&quot; your setup will be empty at the beginning, if you click on the empty field, there should be only one option, if there are none, the color import failed.
For triangulated view, you can use this setup:

Important: This only works with triangles!
If you want to show polygons &gt; 3 vertices, use the Wireframe Modifier and delete the Wireframe and the Multiply node from the setup. The Wireframe Modifier can be used on top of your old geometry, to show both.